1. Field of the Invention
The present invention relates to an airbag that expands to a lateral side of a seated occupant by means of gas introduction.
2. Description of the Related Art
Conventionally, there has been known an airbag device for side impact, which expands an airbag to a lateral side of an occupant sitting in a vehicle's seat to thereby protect the occupant at the time of side face collision, for example.
In addition, as an airbag device of such type, there has been known an airbag device referred to as a side airbag device that is housed in a folded state in a side part of a seat, and that is configured to inflate and expand an airbag between an occupant and a door so as to thereby protect a chest part and a waist part of the occupant. This airbag device also includes: an airbag provided with a bag-shaped airbag main body portion; and an inflator that is housed in a rear side part of this airbag, the inflator being configured to supply a gas.
In addition, in such a side airbag device, there has been known a construction in which the airbag main body portion is partitioned by means of a bulkhead into an upper air chamber for chest part and a lower air chamber for waist part, and a tube passing through the bulkhead on the periphery of an inflator is provided along a vertical direction so as to distribute a gas from the elongated cylindrical inflator to the upper air chamber and the lower air chamber (refer to Japanese Unexamined Patent Application Publication No. 2011-126497, for example.).
However, in the airbag mentioned above, a gas jetted from a gas supply portion of a lower end part that is a tip end part of the inflator remains in the tube, the inflow to the lower air chamber is poor, and a gas configured to flow into the lower air chamber flows in one direction, that is, only toward a lower side, and therefore, there is a need for an additional member or the like for stabilizing an expansion behavior of the airbag.
In particular, in the airbag mentioned above, the gas jetted from the gas supply portion of the inflator directly hits a base cloth that constitutes the airbag main body portion, and thus, in order to disallow constraint of the occupant to become unstable due to such hitting of the gas, it is preferable to mount a patch that is a reinforce member, at the inside of the airbag main body portion, so as to be opposed to the gas supply portion, and however, it is also required that the flow of the gas is not restrained by such a patch.
The present invention has been made in view of such a circumstance, and it is an object of the present invention to provide an airbag that is capable of stabilizing the flow of the gas introduced into the lower air chamber to thereby stabilize an expansion behavior thereof, the air bag being capable of stably constraining an occupant.